JPS60102517A - Integration type measuring method - Google Patents

Abstract

PURPOSE:To maintain high accuracy even though level fluctuation due to drift is yielded, by integrating an electric signal to be measured in two different integrating time zones, and performing subtraction between one integrated value and the other integrated value, which is obtained by the multiplication of several times. CONSTITUTION:A specified fluorescent body 2 is attached to the tip of an optical fiber 1, and a temperature probe is constituted. The fluoresence from the fluorescent body 2 emitted by the excited light from a light emitting device 3 and afterglow are received by a light receiving device 5. Its output is stored in an RAM11 through an amplifier 6, a sample and hold circuit 7, an amplifier 8, and an A/D converter 12. A CPU10 performs integration in two different integrating time zones by adding the stored data in the RAM11. The subtraction between one integrated value and the other integrated value, which is obtained by the multiplication of several times, is performed, and the result is outputted as the measured value.

Description

[Detailed Description of the Invention] Background of the Invention This invention converts light, radiation, electron beams, electromagnetic waves, Shotsuba flow rate, acceleration, temperature, ultrasonic waves, surface acoustic waves, and other physical quantities into electrical signals using sensors. By integrating this electrical signal over a predetermined time period, the above 3! I!
Concerns the integral type measurement method for measuring Φ.

Generally speaking, in this integral type measurement method, the following processing is performed: physical quantity -> conversion into electrical signal by sensor -> amplification -> rectification. FIG. 1 shows how the physical quantities change over time and their integral values. The integration time period T is set from the time when the physical quantity rises ([a) to the time when it becomes almost zero ([C]).The integral type measurement method has the characteristic of being resistant to noise. Even if noise occurs in the electrical conversion signal, as shown by the chain line A, the final integral value at the end of the time period T will change as shown in the integral 1ic I&, L engineering A. There is no change in the IT collection. However, if the level of the physical color signal shifts up and down like a polygon along the broken line B due to the dolly node of the amplifier etc.,
There is a problem that the integral value changes as shown in step 8, and the error caused by this drift cannot be ignored.

SUMMARY OF THE INVENTION An object of the present invention is to enable high accuracy to be maintained in an integral type measurement method even if level fluctuations due to drift occur in a signal to be integrated.

In order to achieve this object, the present invention integrates the electrical signal to be measured in two different integration time periods, subtracts one integral value from the other integral value multiplied by a predetermined number, and It is characterized by using the subtraction result as the measured value.

More specifically, based on the example shown in FIG. 1, it is as follows. ,
When the physical m (electrical signal to be measured) to be integrated is V(t), the above-mentioned integral value IT is given by the following equation.

On the other hand, ζ, according to the method of the present invention, there are two integration time periods r-1 (ta-tb), -r2 (tb ~ tc
) is set. And measurement 11i 1 is the following formula! I can get it.

...(2) ...(3) In equation (3), the drift of the signal V(t) is the integration time period T.
Assume that (ta-tc) is uniform. If it is not uniform, use nα in place of J3 and n in equation (2). Here, α is the degree of variation of drift 1~ In the case of a waveform like ゛ shown in Fig. 1, α
Guaru.

As described above, in the present invention, since signal level fluctuations due to drift are canceled out by subtraction between integral values, highly accurate measurement is possible without being affected by level fluctuations. Since it uses an integral method, it goes without saying that it is resistant to noise.

There are many different methods of integration. The simplest way is to use an integrating circuit that directly integrates the signal in an analog manner. When processing digitally, the signal is sampled at appropriate time intervals, AD converted, and then the sampled data is stored in memory, iiL! It is sufficient to add i-+ the stored IS1 non-bringing data. This is an example of a central processing unit v! i (hereinafter referred to as CI), preferably controlled by a microbrochure. Further, as an integrating means, there is a V/F converter circuit that converts the signal into a pulse signal with a frequency according to the person's preference, and a counting means that counts the output pulses of the V/1: converter circuit to 31 over a predetermined time period.1. s + ijl
III:. A counter or a microprocessor is used as the counting means.

There are several ways to set the interval between the two integrals. One of them is the integration time, i) 1' as mentioned above.
1 (ta ~ lb), 1' 2 (tb ~ tc
) is set in advance. This is the second
As shown in the figure, this effect occurs when the signal under test appears periodically. Integral +1. '1 zone -r 1, -1'
2 can be determined by two types of timing pulses P11 and PI3, and the integrating means can be controlled by these timing pulses.

Timing pulse I) at 21, P22; 3z “J”
It goes without saying that the time periods 1-1 and T2 may be provided separately.

The signal to be measured is not limited to the exponentially decreasing waveform as described above, but may also be a rectangular wave as shown in FIG. 3 or a sine waveform. Applicable to

Another method for determining the integration time 1) is to use the level of the signal under measurement, and this method is suitable for non-periodic signals. As shown in FIG. 4, the reference level ■ rThe signal under test V([) is level-discriminated, and V
(()≧I s o) u, 1 interval -1-I V (1
) < The time zone of IS is spelled as -12. There are four signals for each time period.

...(4) However, the total time period of the time period TL - 1 is the sum (total time) of the time period TL, which is controlled by the timing pulse I) 3 'l, and this pulse 1) 31 becomes 1 level. At some point, input
It can be determined by counting the number of pulses by four. time?
t) The sum of T 2 is also +i'il-like.

For a signal having a steep peak as shown in FIG. 4, it is preferable to perform -C integration using the V/F conversion method described above.

DESCRIPTION OF THE EMBODIMENTS This embodiment is an optical temperature measurement method using a fluorescent material. As shown in FIG. 5, when the phosphor is irradiated with excitation light for the toes, fluorescence and afterglow are generated from the phosphor. Fluorescence is the light that is emitted during excitation, and afterglow is the light that is emitted after the excitation stops and decays over time.

The fluorescence intensity and afterglow time vary depending on the temperature of the atmosphere in which the fluorescent material is placed. Waveforms in Figure 5 (A>Odor
It has a waveform of 0. Coco-C'l' 1111 < Tm
There is a relationship between 2. Generally, the lower the temperature, the higher the luminance and the afterglow time tends to be longer. Instead of directly measuring the luminescence intensity and/or afterglow time, the fluorescence a3 It is possible to measure T->(integrated light amount), and this integrated light m is also a function of Ic temperature.The figure (△) shows the afterglow integrated light amount instead of the afterglow time. For example,
Figure 5 (B) (If you emit 1 ill of light, you can measure the afterglow time instead of fireflies).

In each of these C, the integration time period T is determined in advance. FIG. 5C also shows the integrated light amount of fluorescence and afterglow, which is determined by the integral 114 -1-L; L reference level.

FIG. 6 shows the temperature characteristics of the integrated amount of fluorescence and/or afterglow. Regarding the phosphor used, its integral light fr1'/J) is measured in advance for a hot spring, and the characteristics shown in FIG. 6 are set in advance as a known relationship.

The temperature is determined by comparing the measured integrated light amount with this temperature characteristic.

Figure 7 shows the above-mentioned temperature measurements using fluorescent materials.
An example of how to set two 1-hour poetry intervals is shown. The rising time of the excitation light is 10, and the falling time of the excitation light is tl.
, the time point at which the C afterglow almost disappears at the lowest temperature within the measurement temperature range is defined as t2.

(The integration time period of A> is the case where the afterglow integrated light amount is to be measured. Time t4 is set exactly between the time point and 12, and the time period -ri=ti~t4, King 2-(4 ~12.The quality of both times (+) 1'1 and 1-2 is equal to 1.], and the measured value is...(6).

(1,'3) t;L 11.1 between 11-1.2 5
Divide into equal parts, 11=ti~t6, King 2-L6~[2, l-1
This is the case where point I6 is set so that = 4.1-2. The measured value is expressed by the following formula.

...(7) (C) is an example of the setting example 11) of a platform for measuring the integral amount of fluorescence i1j and afterglow. Time point 1. <Set time I3 between 1 and mouth, King 1 - 3 - t4, King 2 - t6 -
t2, T I = 4 T 2 and "le. 81 Rise bf
j Ha... l) becomes. Since the absolute value is not necessarily required as the measured value (t), it goes without saying that the force shown in Figure 6 should be the same as the measurement conditions for the known function), and equation (8) is as follows. It may be modified as follows.

(D) is -11= t3~t4, T' 2- t5~(
This is the case when 2,1-1=21'2. The measured value is given by the following equation.

... (10) or ...(11) 2 The same (α (value close to 1)) may be set to 8.

Figure 83 shows the 4I configuration of the Tamaro measurement device, and Figure 10 shows its operation in detail.Optical fiber (1)
A predetermined fluorescent substance (2) is removed at the tip of 'tQ.
15L 7 t: 64 +-b are formed. The tip of this temperature probe is placed in an atmosphere or in contact with an object whose temperature is to be measured.

Three types of timing pulse signals are generated from the timing generation circuit (4) controlled by the CPU (10))1.
P2 and P3 are output. Pulse P1 is a light emitter (3)
It is used to drive the circuit, and is output at a constant period Ta (see FIG. 5). This period (d) is set to a time sufficient for the afterglow emitted from the phosphor (2) to completely disappear at all temperatures within the measurement range.

When the pulse P1 is input, excitation light is output from the light emitter (3) and is irradiated onto the CfQ light body (2) passing through the optical fiber (1). The fluorescence and afterglow emitted from the phosphor (2) due to this excitation propagate through the Noah Iba (1), are extracted via the beam splitter (9), and are received by the photoreceiver (5). The detection signal from the photoreceiver (5) is amplified by the preamplifier (6) and then sent to the ripple hold circuit (
7). The photoreceiver (5) is one that has spectral sensitivity so that it detects only fluorescence and afterglow and does not detect excitation light, or the photoreceiver (5) A J filter is installed in front of the filter to block excitation light and allow only fluorescence and afterglow to pass through.

The excitation light from the light receiver (3) is received by a light receiving element (not shown) of the light source monitor (15).

The timing of monitoring the excitation light is pulse P2, J,
It is determined. Pulse 1] 2 is pulse P1 17J l!
; Rise at 7, pulse 1] Rise 1 before the rise of 1;
Ru. The excitation light intensity at the time of output of pulse 1]2 is detected, and the light emitter (3) is controlled based on this detection signal so that the excitation light intensity is always constant (III a1
1 circuit is not shown.

The timing output from the timing generation circuit (4)
Pulses (υ-sampling pulses) P3 are output in 11 pieces between tJ' and J: sea urchin, between stations! 1) t3 and 2 as shown in FIG. a(1, d I N "2,"', ai,...
, aj, ..., an. Also, the period of pulse P3 is multiplied by Δt.

This period Δ[ is an analog-to-digital (AD) converter < 1
It is set to be slightly longer than the ΔD conversion operation 04 in 2).

The timing pulse f]3 is sent to the Zump's small loop circuit (7) and the AD converter (12), and the optical signal (J's small loop) detected by the photoreceiver (5) is The level is held in the hold circuit (7) for each pulse P3.The output of this circuit (7) is amplified by the amplifier circuit (8) and sent to the AD converter (12>), and the output of this circuit (7) is amplified by the amplifier circuit (8).
It is converted to digital 3@ in 1m of RAM (11
).

1 and ΔM<11), 5 days of AD-converted limp ring data are stored as shown in FIG.
The number of repetitions M of J3 and pulse P1 is liL! November 7th is set aside to remember. In this example, the excitation of the fluorescent IA(2) is repeated M times and a measurement 1 is determined based on the average of the 1-ring data at each time point. The soil 11 contains lean-pulling data from the first excitation to the M-th excitation for each sampling time aO to an.
The place where the average value is memorized is marked by the number of M times. Also, for l'<OM(13),
As shown in FIG. 6, the temperature characteristics of the fluorescent light J3 and the integrated afterglow light m are stored, for example, in the form of a Havre.

According to Fig. 8, the temperature measuring device m#yoc p tj (1o>
controlled by Control of this CPU (10)
The Jj and temperature extraction procedure is shown in FIG.

First, the output command of CP(J(,TO>gara pulse 1)1 is output to the timing generation circuit (4),
The timer in 0) starts counting the period ``[a'' (step (21)). Pulse I) from circuit (4)
1, l) 2 are output, and from the time of the fall of the pulse P2, a pulse 3) is output. CPU (10)
Now, wait until time n − r a has elapsed (step (
22)).

During this time, the phosphor (2) was excited, and then the fluorescence J5 and afterglow emitted from the phosphor (2) were sampled every pulse P3 and AD converted. Later, this data is stored in the RAM (11) for each one-no-one sampling time. i! The data is stored in the storage location corresponding to the number of times the data is returned.

1-a is 1il-11, 1i sea (When the timer in 1i times up 4, the number of repetitions M in IkuΔ1νI(11) is decreased by 1 (step (23)), and this result becomes O? It is checked whether (step (24))
, M=0 (step 3), the process returns to step (21), and the excitation of the phosphor (2) and the limp ring of the emission signal are repeated in the same way.

When the measurement of light emission M times is completed, M in RAM (11) is
The sampling data for each sampling I1.
y17. The treetops are removed every 'i' (step (2!+))
, the average of M times is calculated (step (26)).

So, the first integral 1. The average value at the time of rimbling of the limbs belonging to zone 11 is added (?1 power 11
．． ), the integral 111'J between i) -l' 1 is calculated (step (27>).
The average 1ifJ of 113 1-no-1 shilling sentries is added to the integration time period -12, and the average 1ifJ of 113 1-no.
-2 to d) + an integral value is calculated (step (28
) ). For example, if the spear force accepted by (C) in FIG.
~at) is added (II; 'j) (step (2
7) ). Also, −1”2=l (the average value of the sampling data from i to E2 (limbling time points 8j to a11) is added to time period 1-2 for month d (28)). Then, the (8th ) or the measured value I based on equation (9).
is calculated (step (29)). The last calculated measurement 1111 is compared with the temperature function of fluorescence J3 and afterglow integral light, and the thirst is calculated (step (30)).
.

Infrared-visible conversion phosphor YF3: Yll, E as a phosphor
l'. is an infrared light emitting diode (3i:
As a result of measuring the temperature in the manner shown in Fig. 7 (△) using a device similar to that shown in Fig. 8 using QaAs (peak wavelength 940 nm) at 2, it was found that the method was simply to calculate the integral value. In comparison, the error in this invention is about 1.
/3 or less, and the measurement variation is ±0.1 to 0.2
%Met.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram to show the integral type measurement method, and Figures 2 to 4 are the integration times according to this invention. Figure 5 is a waveform diagram for the excitation light and the fluorescence and afterglow emitted from the phosphor, and Figure 6 is the waveform diagram for the fluorescence and afterglow. Fig. 7 is a small diagram showing an example of the integral time period, Fig. 8 is a block diagram showing an example of this defense, and Fig. 9 shows the contents of RAM and ROM. The following diagram, FIG. 10, shows the operation of the circuit 1 shown in FIG. (1)...Optical fiber, (2)...Fluorescent material, (3)
... Light emitter, (4) ... Timing generation circuit, (5
)...Receiver, (7)...Sample/hold circuit, (10)...CI)U, (11)...I(△M,
(13)...1 is OM, (12)...A/D converter. Figure 1 Figure 2 Figure 3 Figure C Temperature* ('C) Figure 7 to tl t2

Claims (6)

[Claims] (1) An integral type in which the electrical signal to be measured is integrated over two different integration time periods, one integral value is subtracted from the other integral value multiplied by a predetermined number, and the result of this subtraction is used for measurement. Measurement method. (2) Sample the electricity to be measured No. 15 at predetermined time intervals and store this sampling data in memory.
[An integral type measurement method according to claim (1)], in which the integral value is calculated by correcting the stored visual numbering data. (3) Integrate the electrical signal to be measured using an integrating circuit,
Scope of patent claims? Integral type measurement method described in A(1). (4) Claim No. 3, in which the electrical signal to be measured is V'/F-converted into a pulse signal with a frequency corresponding to the human movement, and the integral value is calculated by counting the pulses after V/F-conversion.
Integral type measurement method described in section 1). (5) The integral type measurement method according to claim (1), in which two integral time periods are determined from a reference time. (6) The integral type measurement method according to claim (1), wherein two integration time periods are determined by discriminating the electrical signal to be measured based on a reference level.